High-peptization pseudo-boehmite and preparation method thereof

Abstract

The invention relates to high-peptization pseudo-boehmite and a preparation method thereof, and belongs to the technical field of porous aluminum oxide preparation. The method comprises the following steps: obtaining slurry containing pseudo-boehmite colloidal particles; mixing the slurry containing the pseudo-boehmite colloidal particles with an alkaline auxiliary agent to obtain a mixed solution; and aging the mixed solution at a set temperature so as to enable the alkaline additive to perform surface modification on the pseudo-boehmite colloidal particles, thereby obtaining the high-peptizing-solubility pseudo-boehmite. According to the invention, the alkaline auxiliary agent acts on the colloidal particle surface of the pseudo-boehmite at a proper temperature, so that the pore structure of the pseudo-boehmite is maintained, and meanwhile, the pseudo-boehmite with high peptizing property is constructed.

Description

Technical Field

[0001] The present application relates to the technical field of porous alumina preparation, and in particular to a highly colloid-soluble pseudo-boehmite and a preparation method thereof. Background Art

[0002] Porous alumina is widely used in catalysis, adsorption and other fields due to its developed pore structure and good peptization. The developed pore structure can promote the adsorption of various adsorbates, the dispersion of active metals and the diffusion of reactant molecules. Good peptization ensures that the catalyst or adsorbent exists stably in a specific form, which can avoid problems such as powder loss, excessive pressure drop, and component loss during the refining operation or the use of the adsorbent.

[0003] For example, for catalytic cracking catalysts, alumina with a developed pore structure is usually selected as the matrix, and alumina with high peptization solubility is selected as the binder. For hydrogenation catalysts, alumina is required to have both good pore structure and peptization solubility to optimize the pore structure and mechanical strength of the catalyst. For adsorbents, even if molecular sieves are selected as the main adsorption materials, nearly 1 / 3 of alumina or silica sol still needs to be incorporated as a binder. However, if the incorporated binder has a poor pore structure, the application performance of the catalyst and adsorbent will be significantly reduced. Therefore, these materials are required to have both a developed pore structure and good peptization solubility. In order to achieve the above-mentioned purpose, pseudo-boehmite with high peptization solubility is usually selected as an alumina precursor. This is because for conventional alumina precursors, only pseudo-boehmite has good peptization solubility. The formation reasons and regulation methods of pseudo-boehmite peptization solubility are still scientific issues, which urgently need to be solved by scientific researchers. Therefore, it is of great significance to prepare pseudo-boehmite with high peptization solubility. Summary of the invention

[0004] The present application provides a highly peptized pseudo-boehmite and a preparation method thereof, in order to solve the following technical problem: how to improve the peptization solubility of the pseudo-boehmite.

[0005] In a first aspect, the present application provides a method for preparing highly peptized pseudo-boehmite, the method comprising:

[0006] A slurry containing pseudo-boehmite colloid particles is obtained;

[0007] Mixing the slurry containing pseudo-boehmite colloidal particles with an alkaline auxiliary agent to obtain a mixed solution;

[0008] The mixed solution is aged at a set temperature so that the alkaline auxiliary agent can modify the surface of the pseudo-boehmite colloid particles to obtain highly colloid-soluble pseudo-boehmite.

[0009] Optionally, the alkaline auxiliary agent includes at least one of the following: ammonium carbonate, ammonium bicarbonate, sodium carbonate, sodium hydroxide, and ammonia water.

[0010] Optionally, the weight of the alkaline auxiliary agent is 0.1% to 5% of the weight of the alumina in the pseudo-boehmite colloid slurry.

[0011] Optionally, the set temperature is 45°C to 95°C.

[0012] Optionally, the step of obtaining a slurry containing pseudo-boehmite colloid particles comprises:

[0013] The acidic aluminum source is subjected to a neutralization reaction with sodium aluminate to obtain a slurry containing pseudo-boehmite colloid particles.

[0014] Optionally, the acidic aluminum source includes at least one of the following: aluminum sulfate, aluminum chloride, and aluminum nitrate.

[0015] Optionally, the aluminum oxide content of the acidic aluminum source and the sodium aluminate is 45 g / l to 55 g / l, respectively.

[0016] Optionally, the temperature of the neutralization reaction is 45°C to 95°C.

[0017] Optionally, the highly colloid-soluble pseudo-boehmite meets the following indicators: a specific surface area of ​​238.1 m 2 / g~371.5m 2 / g, the pore volume is 0.61ml / g~0.94ml / g, and the peptization index is ≥87.63wt%.

[0018] In a second aspect, the present application provides a highly colloid-soluble pseudo-boehmite, wherein the highly colloid-soluble pseudo-boehmite is prepared by any method described in the first aspect.

[0019] The above technical solution provided by the embodiment of the present application has the following advantages compared with the prior art:

[0020] The preparation method of the peptized pseudo-boehmite provided in the embodiment of the present application comprises: obtaining a slurry of pseudo-boehmite colloid particles; mixing the slurry containing the pseudo-boehmite colloid particles with an alkaline auxiliary agent to obtain a mixed solution; aging the mixed solution at a set temperature so that the alkaline auxiliary agent performs surface modification on the pseudo-boehmite colloid particles to obtain highly peptized pseudo-boehmite. The alkaline auxiliary agent performs surface modification on the pseudo-boehmite colloid particles at a set temperature to optimize the crystal structure of the pseudo-boehmite colloid particles, thereby maintaining the pore structure of the pseudo-boehmite while constructing the high peptization solubility of the pseudo-boehmite, and obtaining a pseudo-boehmite with high peptization solubility. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0022] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the embodiments or the description of the prior art. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0023] Figure 1 A schematic flow chart of a method for preparing highly peptized pseudo-boehmite provided in an embodiment of the present application;

[0024] Figure 2 This is an optical photograph of a highly peptized pseudo-boehmite after peptization provided in Example 3 of the present application;

[0025] Figure 3 This is an optical photograph of a highly peptized pseudo-boehmite after peptization provided in Comparative Example 1 of the present application. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0027] Various embodiments of the present application may be presented in the form of a range; it should be understood that the description in the form of a range is only for convenience and simplicity and should not be understood as a rigid limitation on the scope of the present application; therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and single values ​​within the range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as single numbers within the range, such as 1, 2, 3, 4, 5 and 6, which are applicable regardless of the range. In addition, whenever a numerical range is indicated in this article, it is meant to include any quoted numbers (fractions or integers) within the indicated range. In this article, "at least one" means one or more, and "multiple" means two or more. "At least one", "at least one of the following" or similar expressions refer to any combination of these items, including any combination of single items or plural items. For example, "at least one of a, b, or c", or "at least one of a, b, and c", can all represent: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, c can be single or multiple. In the proportional relationship involved in this article, the parameters that need to be described by proportion should be understood as the first term of the proportional formula in the order of description, and the proportional numbers should be understood as the second term of the proportional formula. For example, the mass ratio of substance A, substance B, and substance C is 1:2:3, then substance A, substance B, and substance C should correspond one-to-one with the proportional numbers in the proportional formula in the order of description, that is, the mass of substance A: the mass of substance B: the mass of substance C = 1:2:3.

[0028] In this application, unless otherwise specified, directional words such as "upper" and "lower" used refer specifically to the directions of the drawings in the accompanying drawings. In addition, in the description of the specification of this application, the terms "include", "comprise", etc. mean "including but not limited to".

[0029] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in this application can be purchased from the market or prepared by existing methods.

[0030] In a first aspect, the present application provides a method for preparing highly colloid-soluble pseudo-boehmite. Figure 1 A schematic diagram of a process for preparing a highly colloid-soluble pseudo-boehmite provided in an embodiment of the present application; see Figure 1 , the method comprising:

[0031] S1, obtaining a slurry containing pseudo-boehmite colloid particles;

[0032] In some embodiments, the step of obtaining a slurry containing pseudo-boehmite colloid particles comprises:

[0033] The acidic aluminum source is subjected to a neutralization reaction with sodium aluminate to obtain a slurry containing pseudo-boehmite colloid particles.

[0034] In some embodiments, the temperature of the neutralization reaction is 45°C to 95°C.

[0035] In some embodiments, the acidic aluminum source includes at least one of the following: aluminum sulfate, aluminum chloride, and aluminum nitrate.

[0036] In some embodiments, the aluminum oxide content of the acidic aluminum source and the sodium aluminate is 45 g / l to 55 g / l, respectively.

[0037] In an embodiment of the present application, an acidic aluminum source and sodium aluminate are subjected to a neutralization reaction to obtain a slurry containing pseudo-boehmite colloid particles. The acidic aluminum source can be a combination of one or more of aluminum sulfate, aluminum chloride, and aluminum nitrate. Generally speaking, the aluminum sulfate-sodium aluminate double aluminum method is commonly used to prepare pseudo-boehmite. The alumina content of the acidic aluminum source and sodium aluminate can be 45g / l to 55g / l, respectively. The pH of the neutralization reaction system is adjusted, and a sufficient amount of alumina is provided to generate pseudo-boehmite colloid particles. Exemplarily, the alumina content of the acidic aluminum source and sodium aluminate can be 45g / l, 46g / l, 47g / l, 49g / l, 51g / l, 53g / l, 55g / l, etc., respectively. The temperature of the neutralization reaction can be 45°C to 95°C, which can make Al 3+ Uniform pseudo-boehmite colloid particles are formed, and the pseudo-boehmite colloid particles have suitable particle size distribution and crystal morphology, laying the foundation for the subsequent formation of pseudo-boehmite. Exemplarily, the temperature of the neutralization reaction can be 45°C, 46°C, 47°C, 48°C, 49°C, 50°C, 52°C, 54°C, 56°C, 58°C, 60°C, 63°C, 65°C, 68°C, 70°C, 73°C, 75°C, 78°C, 80°C, 83°C, 85°C, 88°C, 90°C, 93°C, 95°C, etc. In addition, the neutralization reaction time can be 30min to 40min, and the endpoint pH of the neutralization reaction can be 7.0 to 9.0.

[0038] S2, mixing the slurry containing pseudo-boehmite colloid particles with an alkaline additive to obtain a mixed solution;

[0039] In some embodiments, the alkaline auxiliary agent includes at least one of the following: ammonium carbonate, ammonium bicarbonate, sodium carbonate, sodium hydroxide, and ammonia water.

[0040] In the embodiment of the present application, the alkaline auxiliary agent performs surface modification and crystal modification on the generated pseudo-boehmite colloid particles to form a pseudo-boehmite with high peptization solubility. The peptization solubility of pseudo-boehmite is that the pseudo-boehmite can be quickly and evenly dispersed in an appropriate solvent to form a stable colloidal solution. This excellent peptization performance enables it to better achieve uniform contact and interaction at the molecular level when mixed with other substances, thereby providing a good foundation for preparing high-performance composite materials. The alkaline auxiliary agent can be a combination of one or more of ammonium carbonate, ammonium bicarbonate, sodium carbonate, sodium hydroxide, and ammonia water.

[0041] In some embodiments, the weight of the alkaline auxiliary agent is 0.1% to 5% of the weight of the alumina in the pseudo-boehmite colloid slurry.

[0042] In the embodiment of the present application, the weight of the alkaline auxiliary agent can be 0.1% to 5% of the weight of the aluminum oxide in the pseudo-boehmite colloid slurry. An appropriate amount of the alkaline auxiliary agent can achieve the modification of the pseudo-boehmite colloid particles and make the crystals of the pseudo-boehmite colloid particles grow appropriately. If the weight of the alkaline auxiliary agent is higher than 5% of the weight of the aluminum oxide in the boehmite colloid slurry, the pore structure of the pseudo-boehmite may be destroyed; if the weight of the alkaline auxiliary agent is lower than 0.1% of the weight of the aluminum oxide in the boehmite colloid slurry, it may be difficult to achieve the modification effect on the pseudo-boehmite colloid particles, and thus it is difficult to obtain pseudo-boehmite with high colloidal solubility. Exemplarily, the weight of the alkaline additive can be 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 1.0%, 1.2%, 1.4%, 1.6%, 1.8%, 2.0%, 2.5%, 3.0%, 4.0%, 4.5%, 5.0%, etc., based on the weight of alumina in the pseudo-boehmite colloid slurry.

[0043] S3. Aging the mixed solution at a set temperature so that the alkaline auxiliary agent can modify the surface of the pseudo-boehmite colloid particles to obtain highly colloid-soluble pseudo-boehmite.

[0044] In some embodiments, the set temperature is 45°C to 95°C.

[0045] In the embodiment of the present application, the set temperature can be 45°C to 95°C, that is, the aging temperature can be 45°C to 95°C, which fully realizes the modification effect on the pseudo-boehmite colloid particles, thereby maintaining the pseudo-boehmite pore structure while constructing a high colloid solubility. If the set temperature is higher than 95°C, it may cause the pseudo-boehmite colloid particles to grow excessively and be unfavorable to the improvement of the pseudo-boehmite pore structure; if the set temperature is lower than 45°C, it may cause the pseudo-boehmite colloid particles to grow unevenly and affect the index stability of the pseudo-boehmite. Exemplarily, the set temperature can be 45°C, 46°C, 47°C, 48°C, 49°C, 50°C, 52°C, 54°C, 56°C, 58°C, 60°C, 63°C, 65°C, 68°C, 70°C, 73°C, 75°C, 78°C, 80°C, 83°C, 85°C, 88°C, 90°C, 93°C, 95°C, etc. The neutralization reaction and aging temperature are the same, so it can be understood that the pseudo-boehmite with high peptization solubility is prepared by a one-pot modification strategy, and the preparation method has the advantages of being green and economical, simple to operate, using industrial raw materials, and being suitable for industrial production. In addition, the aged highly peptization solubility pseudo-boehmite slurry is subjected to solid-liquid separation to obtain a filter cake, and the filter cake is dried to obtain a finished product.

[0046] In some embodiments, the highly colloid-soluble pseudo-boehmite meets the following indicators: a specific surface area of ​​238.1 m 2 / g~371.5m 2 / g, the pore volume is 0.61ml / g~0.94ml / g, and the peptization index is ≥87.63wt%.

[0047] In the examples of the present application, the pseudo-boehmite prepared by the above method not only has an excellent pore structure, but also has high peptization solubility. The highly peptized pseudo-boehmite meets the following indicators: the specific surface area is 238.1m 2 / g~371.5m 2 / g, the pore volume is 0.61ml / g~0.94ml / g, and the peptization index is ≥87.63wt%.

[0048] The method for preparing highly peptized pseudo-boehmite provided in the embodiments of the present application has the following advantages:

[0049] 1. The role of alkaline additives

[0050] Alkaline additives play a key role in surface modification of pseudo-boehmite particles. From a chemical point of view, they may react chemically with some active sites on the surface of pseudo-boehmite particles, such as hydroxylation reactions, to change the chemical composition and properties of the particle surface. Alkaline additives may introduce some functional groups on the particle surface that are conducive to dispersion and colloid formation, making pseudo-boehmite easier to disperse evenly during use and showing the characteristics of high colloidal solubility.

[0051] 2. Relationship between surface modification and crystal structure optimization

[0052] The process of surface modification is actually closely related to the optimization of the crystal structure of pseudo-boehmite colloid particles. The crystal structure of pseudo-boehmite itself determines many of its physical and chemical properties, including pore structure. Through surface modification with alkaline additives, the arrangement of atoms on the crystal surface, the state of chemical bonds, etc. may be adjusted, making the crystal structure more regular, stable and conducive to peptization.

[0053] 3. The significance of maintaining pore structure and building high colloidal solubility

[0054] The pore structure of pseudo-boehmite is crucial for its application in many fields (for example, when used as a catalyst carrier, the reactant molecules need to enter the interior through the pores to contact the active sites). Maintaining the pore structure can ensure that its original functions such as adsorption and diffusion are not affected. The construction of high colloidal solubility further broadens its application range, allowing it to be better mixed and synergistic with other substances. For example, in the preparation of composite catalysts, it can be more convenient to be uniformly compounded with active components, etc., to improve the overall performance and meet the strict requirements of different industrial production links for the performance of pseudo-boehmite.

[0055] In general, this preparation method improves the solubility of pseudo-boehmite while ensuring its key structural characteristics through reasonable step design and the use of the special effect of alkaline additives. It is expected to provide a good product foundation for the expansion of pseudo-boehmite in more high-end application fields.

[0056] In a second aspect, the present application provides a highly colloid-soluble pseudo-boehmite, wherein the highly colloid-soluble pseudo-boehmite is prepared by any method described in the first aspect.

[0057] The highly colloid-soluble pseudo-boehmite is realized based on the preparation method of the highly colloid-soluble pseudo-boehmite mentioned above. The specific steps of the preparation method of the highly colloid-soluble pseudo-boehmite can refer to the above embodiment. Since the highly colloid-soluble pseudo-boehmite adopts part or all of the technical solutions of the above embodiment, it at least has all the beneficial effects brought by the technical solutions of the above embodiment, which will not be described one by one here.

[0058] The present application will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are intended only to illustrate the present application and are not intended to limit the scope of the present application. The experimental methods for the unrecorded specific conditions in the following examples are usually measured according to national standards. If there is no corresponding national standard, then carry out according to general international standards, normal conditions or according to the conditions recommended by the manufacturer.

[0059] Example 1

[0060] A method for preparing highly peptized pseudo-boehmite comprises:

[0061] Obtaining a slurry containing pseudo-boehmite colloid particles, comprising neutralizing aluminum sulfate and sodium aluminate to obtain a slurry containing pseudo-boehmite colloid particles; wherein the aluminum sulfate has an aluminum oxide content of 45 g / l, the sodium aluminate has an aluminum oxide content of 55 g / l, the neutralization reaction temperature is 95° C., and the neutralization reaction end point pH=7.0;

[0062] The slurry containing pseudo-boehmite colloid particles is mixed with an alkaline auxiliary agent to obtain a mixed solution; wherein the alkaline auxiliary agent is ammonium carbonate, and the weight of the ammonium carbonate is 0.1% of the weight of the aluminum oxide in the pseudo-boehmite colloid particle slurry;

[0063] The mixed solution is aged at a set temperature so that the alkaline additive can modify the surface of the pseudo-boehmite colloid particles to obtain highly colloid-soluble pseudo-boehmite; wherein the set temperature is 95° C. and the aging time is 2 h.

[0064] Highly colloid-soluble pseudo-boehmite meets the following requirements: Specific surface area is 305.9m 2 / g, the pore volume is 0.72ml / g, and the peptization index is 96.57wt%.

[0065] Example 2

[0066] A method for preparing highly peptized pseudo-boehmite comprises:

[0067] Obtaining a slurry containing pseudo-boehmite colloid particles, comprising neutralizing aluminum sulfate and sodium aluminate to obtain a slurry containing pseudo-boehmite colloid particles; wherein the aluminum sulfate has an aluminum oxide content of 46 g / l, the sodium aluminate has an aluminum oxide content of 53 g / l, the neutralization reaction temperature is 85° C., and the neutralization reaction end point pH=7.5;

[0068] The slurry containing pseudo-boehmite colloid particles is mixed with an alkaline auxiliary agent to obtain a mixed solution; wherein the alkaline auxiliary agent is ammonium bicarbonate, and the weight of the ammonium bicarbonate is 0.5% of the weight of the aluminum oxide in the pseudo-boehmite colloid particle slurry;

[0069] The mixed solution is aged at a set temperature so that the alkaline additive can modify the surface of the pseudo-boehmite colloid particles to obtain highly colloid-soluble pseudo-boehmite; wherein the set temperature is 85° C. and the aging time is 5 hours.

[0070] Highly colloid-soluble pseudo-boehmite meets the following requirements: specific surface area is 293.0m 2 / g, the pore volume is 0.61 ml / g, and the peptization index is 92.15wt%.

[0071] Example 3

[0072] A method for preparing highly peptized pseudo-boehmite comprises:

[0073] Obtaining a slurry containing pseudo-boehmite colloid particles, comprising neutralizing aluminum sulfate and sodium aluminate to obtain a slurry containing pseudo-boehmite colloid particles; wherein the aluminum sulfate has an aluminum oxide content of 47 g / l, the sodium aluminate has an aluminum oxide content of 50 g / l, the neutralization reaction temperature is 75° C., and the neutralization reaction end point pH=8.0;

[0074] The slurry containing pseudo-boehmite colloid particles is mixed with an alkaline auxiliary agent to obtain a mixed solution; wherein the alkaline auxiliary agent is sodium carbonate, and the weight of the sodium carbonate is 1% of the weight of the aluminum oxide in the pseudo-boehmite colloid particle slurry;

[0075] The mixed solution is aged at a set temperature so that the alkaline additive can modify the surface of the pseudo-boehmite colloid particles to obtain highly colloid-soluble pseudo-boehmite; wherein the set temperature is 75° C. and the aging time is 4 hours.

[0076] Highly colloid-soluble pseudo-boehmite meets the following requirements: Specific surface area is 238.1m 2 / g, the pore volume is 0.54 ml / g, and the peptization index is 96.32wt%.

[0077] Example 4

[0078] A method for preparing highly peptized pseudo-boehmite comprises:

[0079] Obtaining a slurry containing pseudo-boehmite colloid particles, comprising neutralizing aluminum sulfate and sodium aluminate to obtain a slurry containing pseudo-boehmite colloid particles; wherein the aluminum sulfate has an aluminum oxide content of 48 g / l, the sodium aluminate has an aluminum oxide content of 47 g / l, the neutralization reaction temperature is 65° C., and the neutralization reaction end point pH=8.5;

[0080] The slurry containing pseudo-boehmite colloid particles is mixed with an alkaline auxiliary agent to obtain a mixed solution; wherein the alkaline auxiliary agent is sodium hydroxide, and the weight of the sodium hydroxide is 2.5% of the weight of the aluminum oxide in the pseudo-boehmite colloid particle slurry;

[0081] The mixed solution is aged at a set temperature so that the alkaline additive can modify the surface of the pseudo-boehmite colloid particles to obtain highly colloid-soluble pseudo-boehmite; wherein the set temperature is 65° C. and the aging time is 3 hours.

[0082] Highly colloid-soluble pseudo-boehmite meets the following requirements: specific surface area is 337.1m 2 / g, the pore volume is 0.87 ml / g, and the peptization index is 90.13wt%.

[0083] Example 5

[0084] A method for preparing highly peptized pseudo-boehmite comprises:

[0085] Obtaining a slurry containing pseudo-boehmite colloid particles, comprising neutralizing aluminum sulfate and sodium aluminate to obtain a slurry containing pseudo-boehmite colloid particles; wherein the aluminum sulfate has an aluminum oxide content of 49 g / l, the sodium aluminate has an aluminum oxide content of 45 g / l, the neutralization reaction temperature is 55° C., and the neutralization reaction end point pH=9.0;

[0086] Mixing the slurry containing pseudo-boehmite colloidal particles with an alkaline auxiliary agent to obtain a mixed solution; wherein the alkaline auxiliary agent is a mixture of sodium carbonate and sodium hydroxide, the weight of the sodium carbonate and the sodium hydroxide is 1:1, and the weight of the mixture of sodium carbonate and sodium hydroxide is 5% of the weight of the aluminum oxide in the pseudo-boehmite colloidal particle slurry;

[0087] The mixed solution is aged at a set temperature so that the alkaline additive can modify the surface of the pseudo-boehmite colloid particles to obtain highly colloid-soluble pseudo-boehmite; wherein the set temperature is 55° C. and the aging time is 2.5 h.

[0088] Highly colloid-soluble pseudo-boehmite meets the following requirements: Specific surface area is 371.5m 2 / g, the pore volume is 0.94 ml / g, and the peptization index is 87.63wt%.

[0089] Example 6

[0090] A method for preparing highly peptized pseudo-boehmite comprises:

[0091] Obtaining a slurry containing pseudo-boehmite colloid particles, comprising neutralizing aluminum sulfate and sodium aluminate to obtain a slurry containing pseudo-boehmite colloid particles; wherein the aluminum sulfate has an aluminum oxide content of 52 g / l, the sodium aluminate has an aluminum oxide content of 45 g / l, the neutralization reaction temperature is 45° C., and the neutralization reaction end point pH=9.5;

[0092] The slurry containing pseudo-boehmite colloid particles is mixed with an alkaline auxiliary agent to obtain a mixed solution; wherein the alkaline auxiliary agent is ammonia water, and the weight of the ammonia water is 3% of the weight of the aluminum oxide in the pseudo-boehmite colloid particle slurry;

[0093] The mixed solution is aged at a set temperature so that the alkaline additive can modify the surface of the pseudo-boehmite colloid particles to obtain highly colloid-soluble pseudo-boehmite; wherein the set temperature is 45° C. and the aging time is 3.5 h.

[0094] Highly colloid-soluble pseudo-boehmite meets the following requirements: Specific surface area is 258.5m 2 / g, the pore volume is 0.74 ml / g, and the peptization index is 92.74wt%.

[0095] Comparative Example 1

[0096] A method for preparing highly peptized pseudo-boehmite comprises:

[0097] Obtaining a slurry containing pseudo-boehmite colloid particles, comprising neutralizing aluminum sulfate and sodium aluminate to obtain a slurry containing pseudo-boehmite colloid particles; wherein the aluminum sulfate has an aluminum oxide content of 55 g / l, the sodium aluminate has an aluminum oxide content of 55 g / l, the neutralization reaction temperature is 65° C., and the neutralization reaction end point pH=8.5;

[0098] The pseudo-boehmite colloid slurry is aged at a set temperature to obtain pseudo-boehmite; wherein the set temperature is 65° C. and the aging time is 5 h.

[0099] Highly colloid-soluble pseudo-boehmite meets the following requirements: Specific surface area is 392.7m 2 / g, the pore volume is 1.23 ml / g, and the peptization index is 41.21 wt%.

[0100] From the analysis of Examples 1 to 6 and Comparative Example 1, it can be seen that the pseudo-boehmite prepared by the above method not only has an excellent pore structure, but also has high peptization solubility. However, the pseudo-boehmite obtained in Comparative Example 1 is not modified by using an alkaline additive, and has a low peptization index. For example, Figure 2 This is an optical photograph of a highly peptized pseudo-boehmite after peptization provided in Example 3 of the present application; Figure 3 This is an optical photograph of a highly peptized pseudo-boehmite after peptization provided in Comparative Example 1 of the present application; see Figures 2-3 , indicating that after the pseudo-boehmite provided in Example 3 and Comparative Example 1 were peptized with 2.5 ml of nitric acid, the sample in Example 3 formed an aluminum sol; however, the sample in Comparative Example 1 mainly existed in the form of precipitation, with obvious stratification. This indicates that an alumina product with good peptization can be well synthesized based on the pseudo-boehmite provided in the examples of the present application.

[0101] One or more technical solutions in the embodiments of the present application also have at least the following technical effects or advantages:

[0102] (1) In the present embodiment, aluminum oxide with a developed pore structure is prepared by an aluminum sulfate-sodium aluminate neutralization method, and an appropriate amount of alkaline additive is additionally added after the neutralization to retain the pore structure as much as possible while improving the peptization solubility of the aluminum oxide;

[0103] (2) The present invention provides a method for preparing highly colloid-soluble porous alumina. The preparation method provided by the present invention has the advantages of being green and economical, simple to operate, using industrial raw materials, and being suitable for industrial production.

[0104] The above description is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest range consistent with the principles and novel features applied for herein.

Claims

1. A method for preparing highly peptized pseudo-boehmite, the method comprising: A slurry containing pseudo-boehmite colloid particles is obtained; Mixing the slurry containing pseudo-boehmite colloidal particles with an alkaline auxiliary agent to obtain a mixed solution; The mixed solution is aged at a set temperature so that the alkaline auxiliary agent can modify the surface of the pseudo-boehmite colloid particles to obtain highly colloid-soluble pseudo-boehmite.

2. The method according to claim 1, characterized in that The alkaline auxiliary agent includes at least one of the following: ammonium carbonate, ammonium bicarbonate, sodium carbonate, sodium hydroxide, and ammonia water.

3. The method according to claim 1 or 2, characterized in that: The weight of the alkaline auxiliary agent is 0.1% to 5% of the weight of the aluminum oxide in the pseudo-boehmite colloid slurry.

4. The method according to claim 1, characterized in that: The set temperature is 45°C to 95°C.

5. The method according to claim 1, characterized in that The method for obtaining the slurry containing pseudo-boehmite colloid particles comprises: The acidic aluminum source is subjected to a neutralization reaction with sodium aluminate to obtain a slurry containing pseudo-boehmite colloid particles.

6. The method according to claim 5, characterized in that The acidic aluminum source includes at least one of the following: aluminum sulfate, aluminum chloride, and aluminum nitrate.

7. The method according to claim 5, characterized in that The aluminum oxide contents of the acidic aluminum source and the sodium aluminate are 45 g / l to 55 g / l, respectively.

8. The method according to claim 5, characterized in that The temperature of the neutralization reaction is 45°C to 95°C.

9. The method according to claim 1, characterized in that: The highly colloid-soluble pseudo-boehmite meets the following indicators: specific surface area is 238.1m 2 / g~371.5m 2 / g, the pore volume is 0.61ml / g~0.94ml / g, and the peptization index is ≥87.63wt%.

10. A highly peptized pseudo-boehmite, wherein the highly peptized pseudo-boehmite is prepared by the method according to any one of claims 1 to 9.

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